Fig. 1: CT-scans through the mid-quadriceps region
of the thigh of two different paraplegic patients,
about 4 years post-injury.
Left - of a patient with a conus
cauda lesion,
right - of a patient with a spastic lesion
THE EU-PROJECT RISE:
USE OF ELECTRICAL STIMULATION TO RESTORE STANDING
IN PARAPLEGICSWITH LONG-TERM DENERVATED DEGENERATED MUSCLES (DDM)
1 Department of Biomedical Engineering and
Physics,
2 L.-Boltzmann-Inst. of Electrical Stimulation and Physical
Rehabilitation, Dept. of
Physical Medicine, Wilhelminenspital,
3 Department of Human
Anatomy and Cell Biology, The University of
SUMMARY
The
article describes the project RISE that was selected for funding by the
European Community FP5 program. The project start is expected for
October/November 2001.
A
novel clinical rehabilitation method for patients suffering from long-term
flaccid paraplegia (denervated degenerated muscles -
DDM) with no chance of recovery of the nervous system,
will be developed. It will restore their muscle fibres (and mass), muscle
function (tetanic contractions, weight bearing) and
thus their ability to rise (’standing up’) and maintain a standing posture
(’standing’). Based on the results of animal experiments on rabbit and pig and
initial clinical trials the associated technology will be developed and an
application for modification of EU-standards is planned. It will provide
European industry with a novel product. The method addresses the needs of about
100 patients per million EU inhabitants.
STATE
OF THE ART
Current
practice in the clinical treatment of patients suffering from muscle denervation and degeneration is unsatisfactory (Fig. 1).
There is no adequate rehabilitation method for patients with long-term denervated degenerated muscles (DDM), caused by peripheral
nerve lesions (plexus paresis, conus cauda lesion, poliomyelitis, multiple sclerosis, etc.).
Fig. 1: CT-scans through the mid-quadriceps region
of the thigh of two different paraplegic patients,
about 4 years post-injury.
Left - of a patient with a conus
cauda lesion,
right - of a patient with a spastic lesion
The
use of electrical stimulation for denervated muscles
is still considered to be controversial by many rehabilitation facilities and
medical professionals. This is largely because current teaching and training
for therapists is still based on the scientific and technological knowledge of
the fifties and sixties.
There
are few basic scientific studies relevant to
The
literature contains a limited number of studies of the effects of long-term
stimulation on denervated muscles in the rat and
rabbit. These have been designed mainly to address basic scientific issues
[Lit. 1, Lit. 2]. In virtually every
case the muscles were denervated only for a short
time before stimulation is commenced, and the results therefore have limited
relevance to this human condition, in which long-standing denervation
has already resulted in severe atrophy and degeneration of muscle fibres. Other
experimental work has been concerned mainly with strategies for reinnervation. A clinical study by Eichhorn
et al. has, however, shown that degeneration after denervation
could be slowed down, even with less than optimal equipment [Lit. 4].
Although there is a substantial literature concerning the electrical
stimulation of paralysed muscle, there are only few published studies that are
directly relevant to muscles that are also denervated.
One
study showed that
To
create more acceptable protocols, we need to acquire a better understanding of
the features of the training regime that induce muscle regeneration and that
improve and maintain endurance and force. We also need to establish safe limits
for stimulation. These and other open questions are to be addressed
systematically in the project.
Technical
equipment for
OBJECTIVES
AND EXPECTED ACHIEVEMENTS
Objective
1: To create a systematic body of basic scientific
knowledge about the restorative effects of electrical stimulation on muscles that have undergone degeneration through long-standing denervation.
Objective
2: To use this knowledge base to design an optimised
protocol for the therapeutic use of electrical stimulation to treat denervated degenerated muscles (DDM) in patients. The protocol
for home use must be effective but must not intrude excessively into the
patient’s normal daily activities.
Objective
3: To assemble a scientific basis for revising existing
EU Regulations governing the use of electrical stimulation, which currently
exclude the possibility of therapeutic use in patients with DDM.
Objective
4: To design, construct, and bring to the point of
commercial adoption, equipment that will enable patients to use the new
therapeutic stimulation protocol safely and effectively in their own homes.
Objective
5: To design, construct, and assess the value of new
diagnostic and measurement equipment (dynamometry, surface accelerometry,
recording of M-wave) for monitoring the progress of the therapy during the
periodic assessment of patients in the clinic.
Expected
achievements:
To
illustrate the way in which this study may be expected to lead to patient
benefits it will be convenient to examine a typical case history.
A
patient suffered a conus cauda
lesion with peripheral denervation in the gluteal region and lower limbs. After the accident he was
operated for stabilization of the spine at T11 – L 1. After one week he was
transferred to the rehabilitation centre for spinal cord injury. Following
wound healing he was instructed in bladder and bowel management, given training
in the use of a wheel chair and in prevention of pressure sores. After 4-6
months he was released from hospital to his home and family. There was little
adaptation of his home and no professional re-integration. He was left to his
own resources to manage daily living. Information was available to him about
training for the muscles of his upper body, but not for his denervated
gluteus and limb muscles.
After
2 months he developed a pressure sore and had to be undergo
plastic surgery with transfer of a musculocutaneous
flap and resection of the ischial tuberosity.
Post-operatively he was required to lay on his stomach
for 4 – 6 months.
He then heard about electrical stimulation and began to seek information
at a specialized clinic. He was anxious to prevent a recurrence of pressure
sores and to acquire a more acceptable cosmetic appearance of his legs during
swimming exercise. He was accepted into the stimulation program.
Now,
3 years later, he stimulates his muscles for about 30 min a day, stands up 20
times a day by means of electrical stimulation, and is satisfied with the
normal appearance of his leg muscles. He feels fit, does not get breathless
when propelling his wheelchair uphill, and although he fell from the wheelchair
during a transfer he did not break any bones. His skin is in good condition and
he is not troubled by pressure sores during his daily and professional
activities.
PROJECT
WORKPLAN
The
objectives will be achieved through an experimental programme conducted in
rabbits, pig and man. The rabbit is the animal of choice for establishing most
quickly and economically the conditions for safe and effective stimulation,
protocols for training and maintenance, and the most appropriate outcome
measures. The results will be used to refine protocols for testing in the pig,
an animal whose musculature is physically more similar to that of man.
Equipment, such as the stimulator devices and electrodes, will be evaluated and
modified in the course of the animal experiments. The equipment and protocols
will be transferred to the clinic for trials to be conducted in patients. Any
problems that arise at this stage will be addressed through further animal
experiments.
The Project is organised as 5
interdisciplinary workpackages which will interact
closely. Each workpackage has its own director.
Within a given workpackage specialists are
responsible for important modules such as developing special technical
equipment, performing an experiment, or conducting laboratory investigations.
The Gantt chart (Fig. 2) shows the time plan of the whole project, divided into
workpackages, and the approximate timing within the workpackages.
REFERENCES
1. Gundersen, K. Determination of muscle contractile
properties: the importance of the nerve.
Acta Physiol Scand 162:
333-341, 1998.
2. Mokrusch,
T., A. Engelhardt, K. Eichhorn, G. Prischenk, H. Prischenk, G. Sack, and B.
Neundorfer. Effects of long-impulse electrical stimulation
on atrophy and fibre type composition of chronically denervated
fast rabbit muscle. J Neurol 237: 29-34, 1990.
3. U.Carraro, C. Catani, L. Saggin, M. Zrunek, M. Scabolcs, H. Gruber, W. Streinzer,
W. Mayr,
H. Thoma: Isomyosin changes after functional electrostimulation
of denervated sheep muscle. Muscle Nerve 11:
1016-1028, 1988.
4. Eichhorn K., Schubert W., David E.: Maintenance, training
and functional use of denervated muscles. J Biomed Eng 6: 205-211, 1984.
5. Valencic V., Vodovnik L., Stefancic
M., Jelnikar T.: Improved motor response due to
chronic electrical stimulation of denervated tibialis anterior muscle in humans. Muscle Nerve 9:
612-617, 1986.
6. H. Kern, C. Hofer, M. Strohhofer,
W. Mayr, W. Richter and H. Stöhr:
Standing up with denervated muscles in humans using
functional electrical stimulation. Artif Organs
23(5):447-452, 1999.
AUTHOR´S ADDRESS
Dr. Winfried Mayr
Department
of Biomedical Engineering and Physics
AKH, Ebene 4/L, Waehringer Guertel 18-20
A-1090
Vienna, Austria
E-mail: w.mayr@bmtp.akh.wien.ac.at
